This invention relates to zinc-rich paint coatings. In particular, this invention is an improvement to aqueous organic ammonium silicate-alkali metal silicate zinc-rich paints.
An aqueous vehicle for a self-curing zinc-rich paint is disclosed in U.S. Pat. No. 3,453,122. This vehicle consists of an organic quaternary ammonium silicate, an alkali metal silicate and hydrous magnesium silicate. The organic and alkali metal silicates act together to provide binding action, while the magnesium silicate provides body to the composition. This system is an excellent corrosion-resistant, zinc-rich coating and at the time provided an advance in the art since the pot-life was extended, when compared to prior art silicate coatings. Unfortunately, successful application of this coating system requires meticulous preparation of the metal surface. It must be sand or grit blasted to a white or near white condition to achieve adequate adhesion.
The art involved in inorganic zinc rich coatings was considered in preparing this application and the previously mentioned U.S. Pat. No. 3,543,122 is considered to be the most relevant prior art to the present invention. U.S. Pat. No. 3,198,820 discloses the preparation of organosilicone-silicate polymers. These patents are hereby incorporated in the present application by reference.